There are already some great games out there for an Olympics themed class but I thought I'd throw these ppts up here with modified/updated dates/times/countries.

There's an intro ppt and a uniform making activity ppt.

Here is another version of this Olympics Lesson PPT, which I edited for my classes.  I added some more information about the Olympics and some more questions and I changed the sports chart to the official Tokyo Olympic Sports Pictograms chart.  I had my students play an Olympic Sports Bingo Game for an activity.  I used a 3x3 Bingo board for grade 3, a 4x4 board for grade four,and a 5x5 for grade 5 & 6, which they can draw in their notebooks.  The students can call "Bingo!" when they've  made three lines.  Much thanks to bananamadi for the original upload.